1. Field of the Invention
The present invention relates to a novel bacteriolytic enzyme and a process for preparing the same using a microorganism of cellular slime mold of Polysphondylium genus.
2. Description of the Related Art
The known methods for rupturing the cell walls may be divided into the three main categories of (1) physical methods, (2) chemical methods and (3) enzymatic methods. The physical and chemical methods involve unavoidable problems concerning the processing systems, and the products are apt to be changed by excessive processing. Enzymatic methods or processes have accordingly been attracting more public attention in recent years.
Enzymes for dissolving germ bodies used for this purpose are generally referred to as bacteriolytic enzymes, and the most popular such enzyme is lysozyme prepared from albumen. However, the bacteriolytic spectrum of the albumen lysozyme only covers some gram-positive bacteria, and the albumen lysozyme has the disadvantage of not acting on general lactic acid bacteria such as typified by the Lactobacillus and Streptococcus genera.
Japanese Patent Publication No. 8597/1982 discloses a method wherein an enzyme composition (containing cellulase, laminarinase, xylanase, pectinase, amylase, protease, etc.) produced by a microorganism of Illupec(?), Coryollus(?) or Coprynus(?) genus of Basidiomycetes is allowed to act on a cell membrane (chlorella membrane) to rupture the membrane. However, this prior art Publication does not refer to any microorganism of Polysphondylium genus.
The growth of a Polysphondylium genus microorganism of cellular slime mold in a simple nutrient medium has been reported in Science, Vol. 139, page 338 (1963). However, no enzyme was extracted from the culture medium after cultivation.
After a vigorous search for a novel enzyme having a bacteriolytic spectrum which is wider than that of albumen lysozyme, we have succeeded in separating a cellular slime mold, more specifically a novel microorganism (novel germ specie) of Polysphondylium, which exhibits a rapid bacteriolytic function on the lactic acid bacteria which have not been attacked by the albumen lysozyme. The present invention is accomplished on the basis of the aforementioned finding.